Metabolic origins and clinical significance of LDL heterogeneity

Statin therapy and cardiovascular protection in type 2 diabetes: The role of baseline LDL-Cholesterol levels. A systematic review and meta-analysis of observational studies

AIM

The guidelines recommend statins to prevent cardiovascular events in patients with type 2 diabetes (T2D) however, the importance of baseline LDL-Cholesterol (LDL-C) levels remains controversial. This study aimed to determine the association of statin use in T2D patients with major adverse cardiovascular events (MACE) and all-cause mortality and whether this association differs by baseline LDL-C levels.

DATA SYNTHESIS

Medline, Embase, and Web of Science were systematically searched from inception until January 2022. Observational studies in patients with T2D comparing statin users vs non-users, with reports of the baseline LDL-C levels, were included. Random-effects meta-analysis and meta-regression were performed to estimate the overall effect on the risk of all-cause mortality and MACE (a composite of myocardial infarction, heart failure, stroke, and revascularization events) and the modification in the association by baseline LDL-C levels. We categorized studies according to their baseline LDL-C levels into 1) <100 mg/dl (2.59 mmol/l), 2) 100-130 mg/dl (2.59-3.37 mmol/l) and 3) >130 mg/dl (3.37 mmol/l) categories. A total of 9 cohort studies (n = 403,411 individuals) fulfilled our criteria. The follow-up duration ranged from 1.7 to 8 years. The overall combined estimate showed that statin therapy was associated with a significantly lower risk of MACE (Hazard Ratio (HR): 0.70 [95% CI 0.59 to 0.83], Absolute risk reduction percentage (ARR%): 3.19% [95%CI 0.88 to 5.50%) and all-cause mortality (HR: 0.60 [95% CI 0.46 to 0.79], ARR%: 5.23% [95% CI 2.18 to 8.28%), but varied, albeit not statistically significant, by baseline LDL-C levels. Studies with baseline LDL-C levels higher than 130 mg/dl had the greatest reduction of MACE (HR: 0.58 [95% CI 0.37 to 0.90]) and all-cause mortality risk (HR: 0.51 [95% CI [ 0.29 to 0.90]). The HRs of MACE in studies with LDL-C levels of 100-130 mg/dl and <100 mg/dl categories were respectively (0.70 [95% CI 0.59 to 0.83]) and (0.83 [95% CI [0.68 to 1.00]); and that of all-cause mortality were respectively (0.62 [95% CI 0.38 to 1.01]) and (0.67 [95% CI [0.44 to 1.02]). Statin use changes the HRs of MACE (0.99 [95%CI, 0.98 to 0.99]; P = 0.04) and all-cause mortality (0.99 [95% CI 0.98 to 1.01]; P = 0.8) per each mg/dl increase in baseline LDL-C level in meta-regression analyses.

CONCLUSION

Statin therapy in patients with T2D was associated with reduced risk of MACE and all-cause mortality. Significant differences across studies with different baseline LDL-C levels were not observed.

Evaluation of measured and calculated small dense low-density lipoprotein in capillary blood and association with the metabolic syndrome

BACKGROUND AND AIMS

Small-dense-low-density-lipoprotein cholesterol (sdLDL-C) is proatherogenic and not commonly measured. The aims were to evaluate capillary blood and its stability for sdLDL-C measurement and measure sdLDL-C in patients with metabolic syndrome (MS).

METHODS

182 patients were studied (49 with MS). sdLDL-C was measured by electrophoresis (LipoPrint®), direct measurement (Roche Diagnostics) and Sampson equation. Intima-media thickness (IMT) and presence of atheroma was evaluated. sdLDL-C was compared in paired venous and capillary blood according to CLSI-EP09c (n = 40). sdLDL-C stability was studied after 24 h at room temperature (RT).

RESULTS

sdLDL-C in capillary blood and venous blood showed agreement with the direct measurement (bias: 4.17 mg/dL, LOA 95 %:-5.66; 13.99) and estimation (bias:8.12 mg/dL, LOA 95 %:-8.59; 24.82). sdLDL-C is stable in capillary blood for 24 h at RT. The electrophoretic method yielded lower (p < 0.05) sdLDL-C than the equation or direct measurement. Patients with MS had (p < 0.05) higher sdLDL-C (%) than patients without MS. Patients with atheroma plaques had higher sdLDL-C (p < 0.05). Estimated sdLDL-C correlated with IMT (r = 0.259, p < 0.001).

CONCLUSIONS

Capillary blood is an alternative to venous blood for sdLDL-C measurement and is stable for 24 h after collection. Estimated and directly measured sdLDL-C associate with the MS being accessible tools for cardiovascular risk assessment.

Effects of portable pedal machines at work on lipoprotein subfraction profile in sedentary workers - the REMOVE study

BACKGROUND

Sedentary behaviour at work is a major cause of atherosclerosis, particularly in tertiary workers. However, no studies have ever assessed the effect of active workstation on lipoprotein subfraction profile. This study aimed to evaluate the effect of 12-week portable pedal machines (PPMs) on lipoprotein subfraction profile among healthy sedentary workers.

METHODS

Healthy administrative workers were randomized into an intervention group using PPMs for 12 weeks or a control group using normal-desk. Lipoprotein subfractions were assessed using Lipoprint® electrophoresis. Main outcomes were explored using mixed models with sensitivity analyses (four models).

RESULTS

We included 40 participants (43.7 ± 8.6 years old, 100% women, BMI 23.8 ± 3.4 kg/m2; sedentary time at work 7.7 ± 1.8 h/day). Groups did not differ at baseline in any outcomes. 32 participants finished the trial. Changes in lipoprotein subfractions were especially marked for LDL profile. There was an interaction time x group for all parameters related to LDL and their subfractions: total LDL-cholesterol (p = 0.012), LDL particle size (p = 0.027), large LDL subfractions 1 and 2 (p = 0.001), and small dense LDL subfractions 3 to 7 (p = 0.046), using the crude model. The interaction reflects difference in the direction of changes between groups. The LDL particle size significantly increased in the intervention group (from 271.9 ± 2.5 at t0 to 272.8 ± 1.9 Ångström at t1, p = 0.037) while it did not change in the control group (272.5 ± 1.7 at t0 to 271.8 ± 1.5Å at t1, p = 0.52). All interactions were constantly significant whatever the models. Influencing variables were mainly stress at work that was associated with an increase in total LDL-cholesterol (coefficient 3.15, 95CI 0.20 to 6.11 mg/dl, p = 0.038), and BMI that was associated with Large-LDL, Large-HDL, IDL-C and triglycerides.

CONCLUSIONS

Lipoprotein profile was improved after a 12-week PPMs intervention at work in healthy administrative workers. Changes were mainly showed for LDL and LDL subfractions. Lipoprotein profile was worsened by stress at work, BMI and age.

TRIAL REGISTRATION

NCT04153214.

Calculated Small Dense Low-Density Lipoprotein Cholesterol Level is A Predominant Predictor for New Onset of Ischemic Heart Disease

AIM

A high level of directly measured small dense low-density lipoprotein cholesterol (sdLDL-C) is a strong risk factor for ischemic heart disease (IHD). However, it remains unclear whether estimated sdLDL-C level is a predictor for IHD. We investigated the associations of new onset of IHD with levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), non-HDL-C, triglycerides (TG), LDL-C and calculated sdLDL-C by Sampson's equation.

METHODS

After exclusion of subjects with IHD or those with TG ≥ 800 mg/dL, a total of 18,176 subjects (men/women: 11,712/6,464, mean age: 46 years) were recruited among 28,990 Japanese individuals who received annual health checkups.

RESULTS

During the 10-year follow-up period, 456 men (3.9%) and 121 women (1.9%) newly developed IHD. Multivariable Cox proportional hazard analyses after adjustment of age, sex, obesity, smoking habit, family history of IHD, estimated glomerular filtration rate, hypertension and diabetes mellitus at baseline showed that the hazard ratio (HR) (1.38 [95% confidence interval: 1.03-1.85]) for new onset of IHD in subjects with the 4th quartile (Q4) of sdLDL-C (≥ 42 mg/dL) was significantly higher than that in subjects with the 1st quartile (Q1) (≤ 24 mg/dL) as the reference, though the adjusted HRs in subjects with Q2-Q4 of TC, HDL-C, non-HDL-C, LDL-C and TG were comparable with those in subjects with Q1 of the respective lipid fractions. The adjusted HR with a restricted cubic spline increased with a higher level of calculated sdLDL-C as a continuous value at baseline.

CONCLUSIONS

sdLDL-C level calculated by Sampson's equation is a predominant predictor for the development of IHD in a general Japanese population.

Changes in soluble LDL receptor and lipoprotein fractions in response to diet in the DIETFITS weight loss study

Circulating levels of the soluble ligand-binding ectodomain of the LDL receptor (sLDLR) that is proteolytically cleaved from the cell surface have been shown to correlate with plasma triglycerides, but the lipid and lipoprotein effects of longitudinal changes in sLDLR have not been examined. We sought to assess associations between changes in sLDLR and detailed lipoprotein measurements between baseline and 6 months in participants in the DIETFITS (Diet Intervention Examining The Factors Interacting with Treatment Success) weight loss trial who were randomly assigned to the low-fat (n = 225) or low-carbohydrate (n = 236) diet arms. sLDLR was assayed using a proteomic procedure, lipids and apoprotein (apo) B and apoAI were measured by standard assays, and lipoprotein particle subfractions were quantified by ion mobility methodology. Changes in sLDLR were significantly positively associated with changes in plasma cholesterol, triglycerides, apoB, large-sized and medium-sized VLDL, and small and very small LDL, and inversely with changes in large LDL and HDL. The lipoprotein subfraction associations with sLDLR were independent of age, sex, diet, and BMI, but all except for large LDL were reduced to insignificance when adjusted for triglyceride change. Principal component analysis identified three independent clusters of changes in lipoprotein subfractions that accounted for 78% of their total variance. Change in sLDLR was most strongly correlated with change in the principal component that was loaded positively with large VLDL and small and very small LDL and negatively with large LDL and HDL. In conclusion, sLDLR is a component of a cluster of lipids and lipoproteins that are characteristic of atherogenic dyslipidemia.

Associations of diet quality and food consumption with serum biomarkers for lipid and amino acid metabolism in Finnish children: the PANIC study

PURPOSE

To investigate the associations of overall diet quality and dietary factors with serum biomarkers for lipid and amino acid metabolism in a general population of children.

METHODS

We studied 194 girls and 209 boys aged 6-8 years participating in the Physical Activity and Nutrition in Children study. Food consumption was assessed by 4-day food records and diet quality was quantified by the Finnish Children Healthy Eating Index (FCHEI). Fasting serum fatty acids, amino acids, apolipoproteins, as well as lipoprotein particle sizes were analyzed with high-throughput nuclear magnetic resonance spectroscopy. Data were analyzed using linear regression adjusted for age, sex, and body fat percentage.

RESULTS

FCHEI was directly associated with the ratio of polyunsaturated (PUFA) to saturated fatty acids (SFA) (PUFA/SFA), the ratio of PUFA to monounsaturated fatty acids (MUFA) (PUFA/MUFA), the ratio of PUFA to total fatty acids (FA) (PUFA%), the ratio of omega-3-fatty acids to total FA (omega-3 FA%), and inversely associated with the ratio of MUFA to total FA (MUFA%), alanine, glycine, histidine and very-low density lipoprotein (VLDL) particle size. Consumption of vegetable oils and vegetable-oil-based margarine (≥ 60% fat) was directly associated with PUFA/SFA, PUFA/MUFA, PUFA%, the ratio of omega-6 FA to total FA (omega-6 FA%), and inversely associated with SFA, MUFA, SFA to total FA (SFA%), MUFA%, alanine and VLDL particle size. Consumption of high-fiber grain products directly associated with PUFA/SFA, PUFA/MUFA, omega-3 FA%, omega-6 FA%, PUFA% and inversely associated with SFA and SFA%. Fish consumption directly related to omega-3 FA and omega-3 FA%. Consumption of sugary products was directly associated with histidine and VLDL particle size. Vegetable, fruit, and berry consumption had direct associations with VLDL particle size and the ratio of apolipoprotein B to apolipoprotein A1. Consumption of low fat (< 1%) milk was directly associated with phenylalanine. A higher consumption of high-fat (≥ 1%) milk was associated with lower serum MUFA/SFA and higher SFA%. Sausage consumption was directly related to SFA% and histidine. Red meat consumption was inversely associated with glycine.

CONCLUSIONS

Better diet quality, higher in intake of dietary sources of unsaturated fat and fiber, and lower in sugary product intake were associated with more favorable levels of serum biomarkers for lipid and amino acid metabolism independent of adiposity.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01803776, registered March 3, 2013.

An increase in calculated small dense low-density lipoprotein cholesterol predicts new onset of hypertension in a Japanese cohort

A disorder of lipid metabolism is involved in cardiovascular diseases including hypertension. A high level of small dense low-density lipoprotein cholesterol (sdLDL-C) is a strong risk factor for atherosclerotic cardiovascular disease. However, the association between sdLDL-C and hypertension has not been fully investigated. We investigated the associations between the development of hypertension during a 10-year period and levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), non-HDL-C, triglycerides (TG), and LDL-C and sdLDL-C calculated by using the Sampson equations in 28,990 Japanese subjects who received annual health examinations. After exclusion of subjects with missing data, those with hypertension, and those with TG ≥ 800 mg/dL at baseline, a total of 15,177 subjects (men/women: 9374/5803, mean age: 46 years) were recruited. During the 10-year period, 2379 men (25.4%) and 724 women (12.5%) had new onset of hypertension. Multivariable Cox proportional hazard model analyses showed that levels of HDL-C, non-HDL-C, TG and sdLDL-C, but not levels of TC and LDL-C, were independent risk factors for the development of hypertension after adjustment of age, sex, family history of hypertension, systolic blood pressure, obesity, current smoking habit, alcohol drinking habit, estimated glomerular filtration rate, diagnosis of diabetes mellitus and use of lipid-lowering drugs and that the adjusted risk of sdLDL-C (per 1-standard deviation) was highest (hazard ratio [95% confidence interval: 1.09 [1.05-1.13]). The addition of sdLDL-C to traditional risk factors for hypertension significantly improved the discriminatory capability, which was better than that of other lipid fractions. In conclusion, a high level of calculated sdLDL-C predicts the development of hypertension.

Dyslipidaemia and growth hormone deficiency - A comprehensive review

Growth hormone deficiency (GHD) is a common complication of several pituitary and hypothalamic disorders and dependent on the onset of disease. It may have severe clinical implications ranging from growth retardation in childhood-onset, to impaired lipid metabolism and increased cardiovascular risk and mortality in adults. GH effectively modulates lipid metabolism at multiple levels and GHD has been associated with an atherogenic lipid profile, that can be reversed by GH replacement therapy. Despite increasing knowledge on the effects of GH on several key enzymes regulating lipid metabolism and recent breakthroughs in the development and wider availability of recombinant GH preparations, several questions remain regarding the replacement therapy in adults with GHD. This review aims to comprehensively summarize the current knowledge on (i) lipid profile abnormalities in individuals with GHD, (ii) proposed mechanisms of action of GH on lipid and lipoprotein metabolism, and (iii) clinical implications of GH replacement therapy in individuals diagnosed with GHD.

Prospective randomized comparative study of the effect of pemafibrate add-on or double statin dose on small dense low-density lipoprotein-cholesterol in patients with type 2 diabetes and hypertriglyceridemia on statin therapy

AIMS/INTRODUCTION

Small dense low-density lipoprotein (sdLDL) is a more potent atherogenic lipoprotein than LDL. As sdLDL-cholesterol (C) levels are determined by triglyceride and LDL-C levels, pemafibrate and statins can reduce sdLDL-C levels. However, it remains unclear whether adding pemafibrate or increasing statin doses would more effectively reduce sdLDL-C levels in patients receiving statin therapy.

MATERIALS AND METHODS

A total of 97 patients with type 2 diabetes and hypertriglyceridemia who were treated with statins were randomly assigned to the pemafibrate 0.2 mg/day addition or statin dose doubled, and followed for 12 weeks. sdLDL-C was measured by our established homogenous assay.

RESULTS

The percentage and absolute reductions of sdLDL-C levels were significantly greater in the pemafibrate add-on group than the statin doubling group (-32.8 vs -8.1%; -16 vs -3 mg/dL, respectively). Triglyceride levels were reduced only in the pemafibrate add-on group (-44%), and LDL-C levels were reduced only in the statin doubling group (-8%), whereas levels of non-high-density lipoprotein-C and apolipoprotein B were similarly decreased (7-9%) in both groups. The absolute reductions of sdLDL-C levels were closely associated with decreased triglyceride, LDL-C, non-high-density lipoprotein-C and apolipoprotein B. In the subgroup analysis, the effect of pemafibrate add-on on sdLDL-C reductions was observed irrespective of baseline lipid parameters or statin type. No serious adverse effects were observed in both groups.

CONCLUSIONS

In patients with type 2 diabetes and hypertriglyceridemia, the addition of pemafibrate to a statin is superior to doubling a statin in reducing sdLDL-C without increasing adverse effects.

Association of LDL-cholesterol subfractions with cardiovascular disorders: a systematic review

BACKGROUND

Cardiovascular disorders (CVDs) are the leading cause of death worldwide. This study aimed to evaluate the association between low-density lipoprotein (LDL) subfractions and cardiovascular disorders.

METHODS

To ensure the rigor of the systematic review, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used. For this systematic review, a comprehensive search strategy was performed in important databases including PubMed, Scopus, Embase, International Statistical Institute (ISI) Web of Science, and google scholar from 2009 to February 2021. The following terms were used for systematic search: low-density lipoprotein, LDL, subfractions, subclasses, nuclear magnetic resonance, NMR, chromatography, high-pressure liquid, HPLC, cardiovascular disease, cerebrovascular, and peripheral vascular disease. Also, for evaluating the risk of bias, the Newcastle-Ottawa scale was employed.

RESULTS

At the end of the search process, 33 articles were included in this study. The results of most of the evaluated studies revealed that a higher LDL particle number was consistently associated with increased risk for cardiovascular disease, independent of other lipid measurements. Also, small dense LDL was associated with an increased risk of CVDs. There was no association between LDL subfraction and CVDs in a small number of studies.

CONCLUSIONS

Overall, it seems that the evaluation of LDL subclasses can be used as a very suitable biomarker for the assessment and diagnosis of cardiovascular diseases. However, further studies are required to identify the mechanisms involved.

Construction and application of artificial lipoproteins using adiposomes

Lipoproteins are complex particles comprised of a neutral lipid core wrapped with a phospholipid monolayer membrane and apolipoproteins on the membrane, which is closely associated with metabolic diseases. To facilitate the elucidation of its formation and dynamics, as well as its applications, we developed an in vitro system in which adiposomes, consisting of a hydrophobic core encircled by a monolayer-phospholipid membrane, were engineered into artificial lipoproteins (ALPs) by recruiting one or more kinds of apolipoproteins, for example, apolipoprotein (Apo) A-I, ApoE, ApoA-IV, and ApoB. In vitro and in vivo studies demonstrated the stability and biological activity of ALPs derived from adiposomes, which resembles native lipoproteins. Of note, adiposomes bearing ApoE were internalized via clathrin-mediated endocytosis following LDLR binding and were delivered to lysosomes. On the other hand, adiposomes bearing ApoA-IV mimicked the existing form of endogenous ApoA-IV and exhibited significant improvement in glucose tolerance in mice. In addition, the construction process was simple, precise, reproducible, as well as easy to adjust for mass production. With this experimental system, different apolipoproteins can be recruited to build ALPs for some biological goals and potential applications in biomedicine.

Low-density lipoprotein subclasses over the menopausal transition and risk of coronary calcification and carotid atherosclerosis: the SWAN Heart and HDL ancillary studies

OBJECTIVE

Perimenopausal women experience a steep increase in low-density lipoprotein cholesterol (LDL-C) that is related to a higher risk of carotid plaque later in life. Low-density lipoprotein subclasses have been linked to cardiovascular diseases beyond LDL-C, promising a better risk stratification. We aim to characterize changes in LDL subclasses and assess their associations with presence of coronary artery calcium (CAC score ≥10) and carotid intima-media thickness (cIMT) over the menopausal transition (MT) and by menopause stage.

METHODS

Nuclear magnetic resonance spectroscopy LDL subclasses were measured for a maximum of five time points. Coronary artery calcification and cIMT were measured for a maximum of two time points. LOESS (locally weighted regression with scatter smoothing) plots, linear mixed-effects models, and generalized estimating equations were used for analyses.

RESULTS

The study included 471 women (baseline: age, 50.2 ± 2.7 years; 79.0% premenopausal/early perimenopausal), of whom 221 had data on CAC or cIMT. Low-density lipoprotein subclasses increased over the MT, whereas intermediate density-lipoprotein particles declined. In adjusted models, higher total LDL particles (LDL-P) and apolipoprotein B were associated with greater CAC prevalence and greater cIMT. Although none of the associations were modified by menopause stage, higher LDL-C, apolipoprotein B, and total LDL-P were associated with greater cIMT during the perimenopause or postmenopause stages, whereas higher LDL-C and small LDL-P were associated with greater CAC prevalence, mainly during perimenopause.

CONCLUSIONS

During the MT, women experience significant increases in LDL subclasses found to be related to greater cIMT levels and CAC prevalence. Whether these changes could better predict future risk of hard cardiovascular disease events beyond LDL-C remains a research question to address.

Use of Apolipoprotein B in the Era of Precision Medicine: Time for a Paradigm Change?

Atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of death worldwide and the risk of a major cardiovascular event is highest among those with established disease. Ongoing management of these patients relies on the accurate assessment of their response to any prescribed therapy, and their residual risk, in order to optimize treatment. Recent international guidelines and position statements concur that the plasma concentration of apolipoprotein B (apoB) is the most accurate measure of lipoprotein associated ASCVD risk. This is especially true for the growing number of individuals with diabetes, obesity, or the metabolic syndrome, and those on statin therapy. Most guidelines, however, continue to promote LDL-C as the primary risk marker due to uncertainty as to whether the greater accuracy of apoB is sufficient to warrant a paradigm shift. Recommendations regarding apoB measurement vary, and the information provided on how to interpret apoB results is sometimes insufficient, particularly for non-lipid specialists. Misinformation regarding the reliability of the assays is also frequently repeated despite its equivalent or better standardization than many other diagnostic assays. Thus, demand for apoB testing is relatively low, which means there is little incentive to increase its availability or reduce its cost. In this review, we examine the results of recent clinical outcomes studies and meta-analyses on the relative values of apoB, LDL-C, and non-HDL-C as markers of ASCVD risk. Although there is seemingly minimal difference among these markers when only population-based metrics are considered, it is evident from our analysis that, from a personalized or precision medicine standpoint, many individuals would benefit, at a negligible total cost, if apoB measurement were better integrated into the diagnosis and treatment of ASCVD.

Accuracy of Small Dense Low-density Lipoprotein-cholesterol Concentration Estimated via Sampson's Equation in Healthy Subjects and Patients with Diabetes

AIM

Sampson et al. proposed a method to calculate small dense low-density lipoprotein-cholesterol (sdLDL-C) concentrations using common lipid measurements, but its accuracy remains unresolved. We examined the difference between Sampson's equation and direct measurement in patients with diabetes.

METHODS

sdLDL-C was measured directly by our established homogeneous assay and estimated by Sampson's equation in patients with diabetes (n=1542) and healthy control subjects (n=673). Large-buoyant (lb)LDL-C was estimated using triglycerides and LDL-C, and sdLDL-C was obtained by subtracting lbLDL-C from LDL-C. The effect of fasting/nonfasting state or lipid-lowering drug therapy on sdLDL-C values was also examined in 30 and 43 patients with diabetes, respectively.

RESULTS

The coefficient of determination (R2) between calculated sdLDL-C and direct measurement was 0.73 and 0.61 for healthy controls and patients with diabetes, respectively. The R2 between calculated sdLDL-C and nonHDL-C or apolipoprotein B was 0.64 and 0.65, respectively. Calculated sdLDL-C was 4-5 mg/dl or 17%-18% higher than the direct measurement. The lower the plasma lipids, especially sdLDL-C, the greater the dissociation between the two methods. Sampson sdLDL-C was also found to give a positive bias when calculated for the nonfasting samples. Statins and pemafibrate significantly reduced sdLDL-C, but their therapeutic effect was underestimated by 5 mg/dl (24%) via Sampson's equation.

CONCLUSIONS

The correlation between Sampson's equation and direct measurements of sdLDL-C was reduced in patients with diabetes. Furthermore, the correlations with nonHDL-C and apolipoprotein B were even higher than those with direct sdLDL-C. The accuracy of Sampson's equation decreased with lower sdLDL-C concentrations and was also influenced by diet.

The LDL-C/ApoB ratio predicts cardiovascular and all-cause mortality in the general population

BACKGROUND

Generally, low-density lipoprotein (LDL) particle size can be inferred from the LDL cholesterol concentration to total apolipoprotein B concentration ratio (LDL-C/ApoB ratio, hereinafter called LAR), which is a good predictor of cardiovascular disease. However, the predictive ability of LAR for mortality risk in the general population is still unclear. This study aimed to explore the association between LAR and cardiovascular as well as all-cause mortality among American adults.

METHODS

The present study was a secondary analysis of existing data from the National Health and Nutrition Examination Survey (NHANES). The final analysis included 12,440 participants from 2005 to 2014. Survival differences between groups were visualized using Kaplan‒Meier curves and the log-rank test. The association of LAR with cardiovascular and all-cause mortality was evaluated using multivariate Cox regression and restricted cubic spline analysis. Age, sex, coronary artery disease, diabetes, lipid-lowering medication use and hypertriglyceridemia were analyzed in subgroup analyses.

RESULTS

The median age in the study cohort was 46.0 years [interquartile range (IQR): 31.0-62.0], and 6,034 (48.5%) participants were male. During the follow-up period, there were 872 (7.0%) all-cause deaths and 150 (1.2%) cardiovascular deaths. Compared with individuals without cardiovascular events, those who experienced cardiovascular deaths had a lower LAR (1.13 vs. 1.25) (P < 0.001). The adjusted Cox regression model indicated that lower LAR was an independent risk factor for both cardiovascular [hazard ratio (HR) = 0.304, 95% confidence interval (CI): 0.114-0.812] and all-cause mortality (HR = 0.408, 95% CI: 0.270-0.617). Moreover, a significant age interaction was observed (P for interaction < 0.05), and there was a strong association between LAR and mortality among participants over 65 years of age. Further analysis showed an inverse association between LAR and both cardiovascular and all-cause mortality.

CONCLUSIONS

LAR can independently predict cardiovascular and all-cause mortality in the general population.

Low-grade inflammation is associated with a heterogeneous lipoprotein subclass profile in an apparently healthy population sample

BACKGROUND AND AIMS

Prevention measures for cardiovascular diseases (CVD) have shifted their focus from lipoproteins to the immune system. However, low-grade inflammation and dyslipidemia are tightly entangled. The objective of this study was to assess the relations between a broad panel of inflammatory biomarkers and lipoprotein subclass parameters.

METHODS

We utilized data from the population-based Study of Health in Pomerania (SHIP-TREND, n = 403). Plasma concentrations of 37 inflammatory markers were measured by a bead-based assay. Furthermore, we employed nuclear magnetic resonance spectroscopy to measure total cholesterol, total triglycerides, total phospholipids as well as the fractional concentrations of cholesterol, triglycerides, phospholipids, ApoA1, ApoA2 and ApoB in all major lipoprotein subclasses. Associations between inflammatory biomarkers and lipoprotein subclasses were analyzed by adjusted linear regression models.

RESULTS

APRIL, BAFF, TWEAK, sCD30, Pentraxin-3, sTNFR1, sTNFR2, Osteocalcin, Chitinase 3-like 1, IFN-alpha2, IFN-gamma, IL-11, IL-12p40, IL-29, IL-32, IL-35, TSLP, MMP1 and MMP2 were related with lipoprotein subclass components, forming two distinct clusters. APRIL had inverse relations to HDL-C (total and subclasses) and HDL Apo-A1 and Apo-A2 content. MMP-2 was inversely related to VLDL-C (total and subclasses), IDL-C as well as LDL5/6-C and VLDL-TG, IDL-TG, total triglycerides as well as LDL5/5-TG and HDL4-TG. Additionally, we identified a cluster of cytokines linked to the Th1-immune response, which were associated with an atherogenic lipoprotein profile.

CONCLUSION

Our findings expand the existing knowledge of inflammation-lipoprotein interactions, many of which are suggested to be involved in the pathogeneses of chronic non-communicable diseases. The results of our study support the use of immunomodulatory substances for the treatment and possibly prevention of CVD.

Is hypertriglyceridemia a reliable indicator of cholesterol-depleted Apo B particles?

OBJECTIVES

Because cholesterol-depleted Apo B particles are thought to be a hallmark of hypertriglyceridemia, American, Canadian and European Lipid Guidelines suggest screening for Apo B only in patients with hypertriglyceridemia. Accordingly, this study examines the relationship of triglycerides to the LDL-C/Apo B and non-HDL-C/Apo B ratios.

METHODS

The study cohort consisted of 6272 NHANES subjects adjusted for a weighted sample size of 150 million subjects without previously diagnosed cardiac disease. Data was reported by LDL-C/Apo B tertiles as weighted frequencies and percent. Sensitivity, specificity, negative predictive and positive predictive values were calculated for triglycerides thresholds of >150 mg/dL and >200 mg/dL. The range of values of Apo B for decisional levels of LDL-C and non-HDL-C were also determined RESULTS: Among patients with triglycerides >200 mg/dL, 75.9% were amongst the lowest LDL-C/Apo B tertile. However, this represents only 7.5% of the total population. Of patients with the lowest LDL-C/Apo B ratio, 59.8% had triglycerides <150 mg/dL. Moreover, there was an inverse relationship between non-HDL-C/Apo B such that elevated triglycerides were associated with the highest tertile of non-HDL-C/Apo B. Finally, the range of values of Apo B for decisional levels of LDL-C and non-HDL-C was determined and is so broad- 30.3-40.6 mg/dl Apo B for different levels of LDL-C and 19.5 to 27.6 mg/dl Apo B for different levels of non-HDL-C- that neither is an adequate clinical surrogate for Apo B.

CONCLUSION

Plasma triglycerides should not be used to restrict the measurement of Apo B since cholesterol-depleted Apo B particles may be present at any level of triglyceride.

Nutrition interventions for adults with dyslipidemia: A Clinical Perspective from the National Lipid Association

Lifestyle habits can have a profound impact on atherosclerotic cardiovascular disease (ASCVD) risk. The National Lipid Association previously published recommendations for lifestyle therapies to manage dyslipidemia. This Clinical Perspective provides an update with a focus on nutrition interventions for the three most common dyslipidemias in adults: 1) low-density lipoprotein cholesterol (LDL-C) elevation; 2) triglyceride (TG) elevation, including severe hypertriglyceridemia with chylomicronemia; and 3) combined dyslipidemia, with elevations in both LDL-C and TG levels. Lowering LDL-C and non-high-density lipoprotein cholesterol are the primary objectives for reducing ASCVD risk. With severe TG elevation (≥500 mg/dL), the primary objective is to prevent pancreatitis and ASCVD risk reduction is secondary. Nutrition interventions that lower LDL-C levels include reducing cholesterol-raising fatty acids and dietary cholesterol, as well as increasing intakes of unsaturated fatty acids, plant proteins, viscous fibers, and reducing adiposity for patients with overweight or obesity. Selected dietary supplements may be employed as dietary adjuncts. Nutrition interventions for all patients with elevated TG levels include restricting intakes of alcohol, added sugars, and refined starches. Additional lifestyle factors that reduce TG levels are participating in daily physical activity and reducing adiposity in patients with overweight or obesity. For patients with severe hypertriglyceridemia, an individualized approach is essential. Nutrition interventions for addressing concurrent elevations in LDL-C and TG include a combination of the strategies described for lowering LDL-C and TG. A multidisciplinary approach is recommended to facilitate success in making and sustaining dietary changes and the assistance of a registered dietitian nutritionist is highly recommended.

Harnessing the Magic of the Dairy Matrix for Next-Level Health Solutions: A Summary of a Symposium Presented at Nutrition 2022

An emerging body of scientific evidence demonstrates that the food matrix-the interaction among nutrients, bioactive components, and physical structure of a food-can affect health in significant, unexpected ways beyond its individual nutrients. In particular, research suggests that consumption of dairy foods such as milk, yogurt, and cheese may affect human health in a matrix-dependent fashion. To disseminate and discuss the growing body of evidence surrounding the role of the dairy food matrix on cardiometabolic health, 3 expert researchers on the topic of the food matrix shared the latest science in a session entitled "Next-Level Health Solutions: The Magic of the Matrix" at the American Society for Nutrition's 2022 LIVE ONLINE Conference. This article is a summary of the literature presented and discussed during that session. A substantial body of literature demonstrates that full-fat dairy foods, particularly fermented dairy foods, may beneficially modulate cardiometabolic outcomes depending on an individual's health status. These findings have important implications for current authoritative dietary guidance that recommends the consumption of low-fat or fat-free dairy foods. Furthermore, this evidence may inform practical applications of harnessing dairy's unique profile of bioactives for health promotion and disease prevention at the individual and community levels.

Sex-specific responses in glucose-insulin homeostasis and lipoprotein-lipid components after high-dose supplementation with marine n-3 PUFAs in abdominal obesity: a randomized double-blind crossover study

Background

Clinical studies on effects of marine-derived omega-3 (n-3) polyunsaturated fatty acids (PUFAs), mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and the plant-derived omega-6 (n-6) PUFA linoleic acid (LA) on lipoprotein-lipid components and glucose-insulin homeostasis have shown conflicting results, which may partly be explained by differential responses in females and males. However, we have lacked data on sexual dimorphism in the response of cardiometabolic risk markers following increased consumption of n-3 or n-6 PUFAs.

Objective

To explore sex-specific responses after n-3 (EPA + DHA) or n-6 (LA) PUFA supplementation on circulating lipoprotein subfractions, standard lipids, apolipoproteins, fatty acids in red blood cell membranes, and markers of glycemic control/insulin sensitivity among people with abdominal obesity.

Methods

This was a randomized double-blind crossover study with two 7-week intervention periods separated by a 9-week washout phase. Females (n = 16) were supplemented with 3 g/d of EPA + DHA (fish oil) or 15 g/d of LA (safflower oil), while males (n = 23) received a dose of 4 g/d of EPA + DHA or 20 g/d of LA. In fasting blood samples, we measured lipoprotein particle subclasses, standard lipids, apolipoproteins, fatty acid profiles, and markers of glycemic control/insulin sensitivity.

Results

The between-sex difference in relative change scores was significant after n-3 for total high-density lipoproteins (females/males: -11%*/-3.3%, p = 0.036; *: significant within-sex change), high-density lipoprotein particle size (+2.1%*/-0.1%, p = 0.045), and arachidonic acid (-8.3%*/-12%*, p = 0.012), and after n-6 for total (+37%*/+2.1%, p = 0.041) and small very-low-density lipoproteins (+97%*/+14%, p = 0.021), and lipoprotein (a) (-16%*/+0.1%, p = 0.028). Circulating markers of glucose-insulin homeostasis differed significantly after n-3 for glucose (females/males: -2.1%/+3.9%*, p = 0.029), insulin (-31%*/+16%, p < 0.001), insulin C-peptide (-12%*/+13%*, p = 0.001), homeostasis model assessment of insulin resistance index 2 (-12%*/+14%*, p = 0.001) and insulin sensitivity index 2 (+14%*/-12%*, p = 0.001), and quantitative insulin sensitivity check index (+4.9%*/-3.4%*, p < 0.001).

Conclusion

We found sex-specific responses after high-dose n-3 (but not n-6) supplementation in circulating markers of glycemic control/insulin sensitivity, which improved in females but worsened in males. This may partly be related to the sex differences we observed in several components of the lipoprotein-lipid profile following the n-3 intervention.

Clinical trial registration

https://clinicaltrials.gov/, identifier [NCT02647333].

Associations Between Serum Folate Level and HOMA-IR in Chinese Patients with Type 2 Diabetes Mellitus

Background

Adequate intake of folic acid (FA) has been proven essential for metabolism, cellular homeostasis, and antioxidant effects in diabetic patients. Our aim was to evaluate the association between serum folate levels and the risk of insulin resistance in patients with type 2 diabetes mellitus (T2DM) and to provide new ideas and approaches for reducing the risk of T2DM.

Methods

This was a case-control study involving 412 participants (206 with T2DM). Anthropometric parameters, islet function, biochemical parameters and body composition of T2DM group and control group were determined. Correlation analysis and logistic regression were used to evaluate the risk factors associated with the onset of insulin resistance in T2DM.

Results

The folate levels in type 2 diabetic patients with insulin resistance were significantly lower than those in patients without insulin resistance. Logistic regression showed that FA and high-density lipoprotein were independent influencing factors for insulin resistance in diabetic patients (P < 0.05). After adjusting for confounding factors, the degree of insulin resistance in diabetic patients was in a significant inverse relationship with folate levels (P< 0.05). We also found that below the serum FA threshold of 7.09 ng/mL insulin resistance was significantly more elevated.

Conclusion

Our findings suggest that the risk of insulin resistance increases with the decrease in serum FA levels in T2DM patients. Monitoring folate levels in these patients and FA supplementation are warranted preventive measures.

Exosomal non-coding RNAs: Emerging therapeutic targets in atherosclerosis

Atherosclerosis is an LDL-driven and inflammatory disorder of the sub-endothelial space. Available data have proposed that various factors could affect atherosclerosis pathogenesis, including inflammation, oxidation of LDL particles, endothelial dysfunction, foam cell formation, proliferation, and migration of vascular smooth muscle cells (VSMCs). In addition, other research indicated that the crosstalk among atherosclerosis-induced cells is a crucial factor in modulating atherosclerosis. Extracellular vesicles arenanoparticleswith sizes ranging from 30-150 nm, playing an important role in various pathophysiological situations. Exosomes, asa form of extracellular vesicles, could affect the crosstalk between sub-endothelial cells. They can transport bioactive components like proteins, lipids, RNA, and DNA. As an important cargo in exosomes, noncoding RNAs (ncRNAs) including microRNAs, long noncoding RNAs, and circular RNAs could modulate cellular functions by regulating the transcription, epigenetic alteration, and translation. The current work aimed to investigate the underlying molecular mechanisms of exosomal ncRNA as well as their potential as a diagnostic biomarker and therapeutic target in atherosclerosis.

Remnant cholesterol can identify individuals at higher risk of metabolic syndrome in the general population

Remnant cholesterol (RC) is a highly atherogenic lipid. Previous studies have shown that RC was closely associated with many metabolism-related diseases. However, the relationship of RC with metabolic syndrome (MetS) remains unclear. This study's objective is to investigate the relationship of RC with MetS. A total of 60,799 adults who received health assessments were included in this study. RC was calculated by subtracting the directly measured values for low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) from total cholesterol (TC) and divided into 5 groups according to its quintile. MetS diagnosis according to National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) definitions. Application of receiver operating characteristic (ROC) curve analysis and multivariate logistic regression to assess the association of RC with MetS. In RC quintile groups, the prevalence of MetS was 0.84, 1.10, 1.92, 3.87 and 37.71%, respectively. Multivariate logical regression analysis showed that RC and MetS maintained a stable independent positive correlation between both sexes. An interaction test further showed that the MetS risk associated with RC was significantly higher in women than in men. Moreover, ROC analysis results showed that RC had high accuracy in identifying MetS, especially among young and middle-aged men [(area under the curve: AUC) < 30 years: 0.9572, 30-39 years: 0.9306, 40-49 years: 0.9067]. The current study provided the first evidence of a positive association between RC and MetS, and that this correlation was stronger in women than in man, which may be due to the relative deficiency of estrogen in women.

Can Electronegative LDL Act as a Multienzymatic Complex?

Electronegative LDL (LDL(-)) is a minor form of LDL present in blood for which proportions are increased in pathologies with increased cardiovascular risk. In vitro studies have shown that LDL(-) presents pro-atherogenic properties, including a high susceptibility to aggregation, the ability to induce inflammation and apoptosis, and increased binding to arterial proteoglycans; however, it also shows some anti-atherogenic properties, which suggest a role in controlling the atherosclerotic process. One of the distinctive features of LDL(-) is that it has enzymatic activities with the ability to degrade different lipids. For example, LDL(-) transports platelet-activating factor acetylhydrolase (PAF-AH), which degrades oxidized phospholipids. In addition, two other enzymatic activities are exhibited by LDL(-). The first is type C phospholipase activity, which degrades both lysophosphatidylcholine (LysoPLC-like activity) and sphingomyelin (SMase-like activity). The second is ceramidase activity (CDase-like). Based on the complementarity of the products and substrates of these different activities, this review speculates on the possibility that LDL(-) may act as a sort of multienzymatic complex in which these enzymatic activities exert a concerted action. We hypothesize that LysoPLC/SMase and CDase activities could be generated by conformational changes in apoB-100 and that both activities occur in proximity to PAF-AH, making it feasible to discern a coordinated action among them.

Estimated small dense low-density lipoprotein-cholesterol and incident type 2 diabetes in Japanese people: Population-based Panasonic cohort study 13

AIMS

This study aimed to investigate the association between estimated small dense low-density lipoprotein (sd-LDL) and incident type 2 diabetes.

METHODS

We analyzed the data from a health checkup under a program conducted by Panasonic Corporation between 2008 and 2018. A total of 120,613 participants were included, of whom 6,080 developed type 2 diabetes. Estimated large buoyant (lb)-LDL cholesterol and sd-LDL cholesterol was calculated by the formula using triglyceride and LDL cholesterol. Cox proportional hazard model and time-dependent receiver operating characteristic (ROC) analysis were used to evaluate the association between the lipid profiles and incident type 2 diabetes.

RESULTS

Multivariate analysis showed that LDL cholesterol, high-density lipoprotein (HDL) cholesterol, triglyceride, estimated large buoyant (lb)-LDL cholesterol, and estimated sd-LDL were associated with incident type 2 diabetes. Moreover, the area under the ROC curve and optimal cut-off values for estimated sd-LDL cholesterol for incident type 2 diabetes at 10 years were 0.676 and 35.9 mg/dL, respectively. The area under the curve of estimated sd-LDL cholesterol was higher than that of HDL cholesterol, LDL cholesterol, or estimated lb-LDL cholesterol.

CONCLUSION

The estimated sd-LDL cholesterol was an important predictor of future incidence of diabetes within 10 years.

Exploring the Association between Low-Density Lipoprotein Subfractions and Major Adverse Cardiovascular Outcomes—A Comprehensive Review

Cardiovascular disease (CVD) impacts hundreds of millions of people each year and is the main cause of death worldwide, with atherosclerosis being its most frequent form of manifestation. Low-density lipoproteins (LDL) have already been established as a significant cardiovascular risk factor, but more recent studies have shown that small, dense LDLs are the ones more frequently associated with a higher overall risk for developing atherosclerotic cardiovascular disease. Ever since atherogenic phenotypes were defined for the first time, LDL subfractions have been continuously analyzed in order to identify those with a higher atherogenic profile that could further become not only high-accuracy, effective prognostic biomarkers, but also treatment targets for novel lipid-lowering molecules. This review sets out to comprehensively evaluate the association between various LDL-subfractions and the risk of further developing major adverse cardiovascular events, by assessing both genetical and clinical features and focusing on their physiopathological characteristics, chemical composition, and global ability to predict long-term cardiovascular risk within the general population. Further research is required in order to establish the most beneficial range of LDL-C levels for both primary and secondary prevention, as well as to implement LDL subfraction testing as a routine protocol, separately from the general assessment of the other traditional cardiovascular risk factors.

Effects of Free Linoleic Acid and Oleic Acid in Sesame Meal Extract as Pancreatic Lipase Inhibitors on Postprandial Triglyceridemia: A Randomized, Double-Blind, Placebo-Controlled, Crossover Study in Healthy Volunteers

A great number of chemically diverse pancreatic lipase (PL) inhibitors have been identified to tackle obesity; however, very few of them have entered clinical studies. The ethanolic extract of sesame meal is a potent PL inhibitor, and its activity hinges exclusively on two free fatty acids: linoleic acid and oleic acid, which were proven to reduce postprandial triglyceride excursion in rats. Herein, to investigate the clinical efficacy of the sesame meal extract, in a crossover trial, 30 healthy volunteers were randomized to receive the sesame meal extract containing experimental food or placebo along with a high-fat meal. Treatment with the sesame meal extract significantly lowered the incremental postprandial serum triglyceride concentration and reduced the incremental area under the curve (iAUC) by 16.8% (p-value = 0.03) compared to placebo. Significant decreases in postprandial remnant-like lipoprotein particle cholesterol and low-density lipoprotein particles were also observed, whereas high-density lipoprotein cholesterol was increased. These results suggest that treatment with the sesame meal extract significantly reduced the postprandial excursion of triglycerides and improved the lipidemic profile after high dietary fat intake in healthy individuals, indicating the substantial potential of free linoleic acid and oleic acid and natural products rich in these compounds for the management of obesity and related conditions.

Small Dense Low-Density Lipoprotein Cholesterol and Ischemic Stroke

OBJECTIVE

For decades, it has been suggested that small dense low-density lipoprotein (sdLDL) may be particularly atherogenic. High levels of sdLDL are associated with an increased risk of ischemic heart disease; however, the association of sdLDL with ischemic stroke has not been explored in a large prospective study on the general population. We tested the hypothesis that high sdLDL cholesterol levels are associated with an increased risk of ischemic stroke.

METHODS

This prospective study included 38,319 individuals from the Copenhagen General Population Study with fresh sample measurements of sdLDL cholesterol. Median follow-up time was 3.1 years. We observed 302 and 74 ischemic and hemorrhagic strokes from baseline in 2013 to 2017 to the end of follow-up in 2018. For comparison, we included estimates for large buoyant LDL cholesterol and total LDL cholesterol.

RESULTS

Higher levels of sdLDL cholesterol were log-linearly associated with increased risk of ischemic stroke. Compared with individuals with sdLDL cholesterol in the lowest tertile (≤0.60 mmol/l; ≤23 mg/dl) the multivariable adjusted hazard ratio for ischemic stroke was 1.79 (95% confidence interval = 1.31-2.43) for the highest tertile (≥0.86 mmol/l; ≥33 mg/dl). Multivariable adjusted hazard ratios for ischemic stroke per 1 mmol/l (38.7 mg/dl) higher levels were 1.69 (1.28-2.22) for sdLDL cholesterol, 0.95 (0.78-1.16) for large buoyant LDL cholesterol, and 1.08 (0.93-1.25) for total LDL cholesterol. Hazard ratios were similar when further adjusting for body mass index (BMI) and diabetes mellitus in the biological pathway in combination with related lipids and lipoproteins.

INTERPRETATION

Higher sdLDL cholesterol levels were robustly associated with increased risk of ischemic stroke. ANN NEUROL 2023.

Circadian Rhythm of Subspecies of Low-Density Lipoprotein-Cholesterol and High-Density Lipoprotein-Cholesterol in Healthy Subjects and Patients with Type 2 Diabetes

AIMS

We established automated assay kits for quantifying small dense low-density lipoprotein (sdLDL)-cholesterol (C), LDL-triglyceride (TG), and high-density lipoprotein (HDL)3-C, and apolipoprotein (apo)E-rich HDL-C, and these have been recognized as sensitive biomarkers for predicting coronary artery disease. We investigated the circadian rhythms of these novel lipids to determine if fasting is required to determine basal levels.

METHODS

Forty-eight inpatients with type 2 diabetes and 19 healthy volunteers were studied. Blood samples were collected at seven time points, which were obtained after an overnight fast, before and 2 h after each meal, and before the next breakfast. sdLDL-C, LDL-TG, remnant-like particle (RLP)-C, TG-rich lipoprotein (TRL-C), HDL3-C, and apoE-rich HDL-C were measured by the homogeneous methods. NonHDL-C, large buoyant (lb)LDL-C and HDL2-C were calculated by subtracting sdLDL-C from LDL-C or HDL3-C from HDL-C, respectively.

RESULTS

Serum TG levels were significantly increased after meals in both healthy participants and patients with diabetes. RLP-C and TRL-C were also increased postprandially. LDL-TG, LDL-C, nonHDL-C, HDL2,3-C, and apoE-rich HDL-C did not exhibit significant fluctuation during the day in healthy participants and patients with diabetes. sdLDL-C was slightly increased postprandially in subjects with diabetes (1-2 mg/dl, 3%-9%), though its increase was not significant compared to the baseline (fasting) level. Significant postprandial reduction was observed with LDL-C and lbLDL-C. There was no influence of statin therapy or oral anti-diabetes drugs on the circadian rhythm of LDL-C subspecies.

CONCLUSIONS

Subtle postprandial increase in sdLDL-C is considered a negligible level in general clinical practice. Fasting is not mandatory to measure basal concentrations of LDL and HDL subspecies.

Estimation of Small Dense LDL-Cholesterol Levels in Patients with Acute Coronary Syndrome

Small dense LDL-cholesterol is an established risk factor for atherosclerosis, but it is not routinely measured in clinical practice, and its measurement has not yet been reimbursed. The Sampson equation that uses triglyceride and LDL-cholesterol levels has very recently been proposed to estimate small dense LDL-cholesterol levels. We validated its accuracy in patients with acute coronary syndrome.Serum samples were obtained on admission from hospitalized patients with acute coronary syndrome before heparinization. Small dense LDL-cholesterol levels were measured directly and were also estimated from triglyceride and LDL-cholesterol levels using the Sampson equation. The correlation between the Sampson's equation and direct measurement was investigated.A total of 55 patients were enrolled. The median age was 75 (65, 84) years old, and 35 (64%) were men. There was a moderate correlation between the two methods (r = 0.76, P < 0.001). A lower level of small dense LDL-cholesterol was independently associated with a greater overestimation of the Sampson equation.The Sampson equation is useful for estimating small dense LDL-cholesterol levels in patients with acute coronary syndrome. However, the estimated value may be overestimated in patients with low lipid profiles.

Associations among carotid plaque progression, cerebrovascular/cardiovascular diseases and LDL-C/non-HDL-C goal achievement in diabetic patients: A retrospective cohort study

BACKGROUND

Impaired glycolipid metabolism can induce vascular injury and plaque formation. It is important to investigate the associations between carotid plaque progression and lipid-lowering goal achievement and cardiovascular disease.

METHODS

Diabetic patients who underwent at least 2 carotid ultrasound scans with intervals ≥0.5 years and were hospitalized in the Department of Endocrinology at Sun Yat-sen Memorial Hospital were included. Patients were divided into 3 groups based on carotid plaque progression: the persistent plaque absence, new-onset plaque and persistent plaque presence groups. The primary outcomes were CHD and stroke, while the secondary outcomes were low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C) goal achievement.

RESULTS

There were 304 diabetic patients included, with a median follow-up period of 2.15 years. In multivariable logistic regression analysis, persistent plaque presence was positively associated with a 2.285-fold increase in coronary heart disease (CHD) prevalence, while new-onset plaque was associated with a 3.225-fold increase in stroke prevalence compared to persistent plaque absence in patients with follow-up periods ≥ 0.5 years. The association remained significant in patients with a follow-up period ≥ 1 year and ≥2 years. The velocity of average plaque length change was independently associated with increased ΔLDL-C (last - goal) (β = 0.073, P = 0.048).

CONCLUSION

Carotid plaque progression had long-term association with CHD and stroke starting from 0.5 years, while the velocity of average plaque length associated with increased ΔLDL-C (last - goal) might reflect patient response to statins. Repeated carotid plaque measurements might guide lipid-lowering therapies.

Efficacy of Low-dose Dapagliflozin in Young People with Type 1 Diabetes

Objective Young people with type 1 diabetes are likely to gain body weight and not achieve optimal glycemic control with only high doses of insulin. This study examined the efficacy of the sodium-glucose cotransporter 2 (SGLT2) inhibitor dapagliflozin as an adjunct-to-insulin therapy in young Japanese subjects with type 1 diabetes who had been diagnosed before 15 years old, were overweight, and had inadequate control despitereceiving intensive insulin therapy. Methods Twenty-two patients with type 1 diabetes (12 boys and 10 girls 16.0-33.9 years old) were involved in the study. All patients had a body mass index (BMI) >25 kg/m², glycated hemoglobin (HbA1c) level >7.0%, and daily insulin dose >0.5 units/kg. They were treated with a low dose of dapagliflozin (5.0 mg/day) as an adjunctive therapy to insulin. Fourteen patients were treated with multiple daily injections of insulin, while eight used an insulin pump. Results The body weights and BMIs were significantly reduced during the 12-month study period (change of -4.4 kg and -1.7 kg/m², p<0.001, respectively). Their insulin dose was significantly decreased (-0.17 units/kg, P <0.001), and glycemic control was significantly improved (fasting plasma glucose: -18.7 mg/dL, HbA1c: -0.62%, p<0.001) during the study period. There was one episode of diabetic ketoacidosis, with no other problematic adverse events, including severe hypoglycemia, observed. Conclusion The use of low-dose dapagliflozin as an adjunct therapy may be beneficial in overweight young people with poorly controlled type 1 diabetes.

The human liver lipidome is significantly related to the lipid composition and aggregation susceptibility of low-density lipoprotein (LDL) particles

BACKGROUND AND AIMS

The susceptibility of low-density lipoprotein (LDL) to aggregation predicts atherosclerotic cardiovascular disease. However, causes of interindividual variation in LDL lipid composition and aggregation susceptibility remain unclear. We examined whether the lipid composition and aggregation susceptibility of LDL reflect the lipid composition of the human liver.

METHODS

Liver biopsies and blood samples for isolation of LDL particles were obtained from 40 obese subjects (BMI 45.9 ± 6.1 kg/m², age 43 ± 8 years). LDL was isolated using sequential ultracentrifugation and lipidomic analyses of liver and LDL samples were determined using ultra-high performance liquid chromatography-mass spectrometry. LDL aggregation susceptibility ex vivo was analyzed by inducing aggregation by human recombinant secretory sphingomyelinase and following aggregate formation.

RESULTS

The composition (acyl carbon number and double bond count) of hepatic triglycerides, phosphatidylcholines, and sphingomyelins (SMs) was closely associated with that of LDL particles. Hepatic dihydroceramides and ceramides were positively correlated with concentrations of the corresponding SM species in LDL as well with LDL aggregation. These relationships remained statistically significant after adjustment for age, sex, and body mass index.

CONCLUSIONS

Lipid composition of LDL reflects that of the human liver in obese patients. Changes in hepatic sphingolipid metabolism may contribute to interindividual variation of LDL lipid composition and susceptibility to aggregation.

The pattern of dyslipidemia among Somali type 2 diabetic patients: a cross-sectional study

BACKGROUND

Diabetes mellitus (DM) is a major public health concern. This study aims to determine frequency, pattern, and potential determinants of dyslipidemia among adults with type 2 DM (T2DM) at Somalia's only diabetes outpatient clinic.

METHODS

Five hundred twenty-nine consecutive patients with T2DM who applied to our outpatient clinic between January 2020 and June 2020 were included in this cross-sectional hospital-based study. Demographic characteristics of participants, including lipid panel, were extracted from the registry system. Correlation analysis was performed between lipid profile and related parameters. Multivariate binary logistic regression models were used to identify independent determinants of dyslipidemia for further analysis.

RESULTS

The overall population's mean age was 51.9 ± 12.2 years, with 177 (33.5%) males. Total and atherogenic dyslipidemias were found in 92.8% and 24.8%, respectively. The most common isolated pattern of dyslipidemia was high non-high-density lipoprotein cholesterol (non-HDL-C) (82.8%), followed by high low-density lipoprotein cholesterol (LDL-C) (72.6%), high total cholesterol (TC) (54.3%), and low HDL-C (48.3%). Females were found to have a higher prevalence of high TC (63.4% vs. 54.2%, p = 0.043) and lower HDL-C (57.4% vs. 46.3%, p = 0.016). High LDL-C with low HDL-C was the most common pattern among combined type dyslipidemias (18.1%), followed by high LDL-C with high triglyceride (TG) (17.8%), as well as low TG with low HDL-C (3.6%). Females had a higher proportion of high LDL-C with low HDL-C than males (20.3% vs. 13.6%, p = 0.036). Age, gender, body mass index, central obesity, spot urinary proteinuria, fasting blood glucose, poor glycemic control, creatinine, and Hs-CRP were all associated with different dyslipidemia patterns in multivariate logistic regression analyses.

CONCLUSIONS

We found that the prevalence of dyslipidemia, especially atherogenic patterns, was extremely high among Somali T2DM patients. An enhanced health policy should, therefore, be established to detect, treat and prevent dyslipidemia.

Clinical significance of neutrophil gelatinase-associated lipocalin and sdLDL-C for coronary artery disease in patients with type 2 diabetes mellitus aged ≥ 65 years

BACKGROUND AND AIMS

Although type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD) share many common pathological and physiological characteristics, there are few studies assessing the predictive capacity of novel biomarkers in occurrence and development of CAD in T2DM patients aged ≥ 65 years. In addition, T2DM patients aged ≥ 65 years are prone to CAD. Therefore, it is of great significance to find novel biomarkers for the development CAD in T2DM.

METHODS

In this retrospective cohort study, 579 T2DM patients aged ≥ 65 years were consecutively enrolled in this work, and 177 of whom had major adverse cardiovascular and cerebrovascular events (MACCE: cardiovascular or cerebrovascular death, acute coronary syndrome, coronary stent implantation, and stroke) during the follow up. Univariate and multivariate factors were employed to analyze the correlation between each variable and the occurrence of MACCE, and the Spearman's rank correlation analysis was performed to assess the relationships between Neutrophil gelatinase-associated lipocalin (NGAL) and small dense low-density lipoprotein-cholesterol (LDL-C) (sdLDL-C). The receiver operating characteristic (ROC) curve was adopted to determine the predictive value of NGAL and sdLDL-C elevation for MACCE in T2DM patients aged ≥ 65 years.

RESULTS

After a median 48 months follow-up [19, (10 ~ 32) ], the levels of NGAL, sdLDL-C, hemoglobin A1c (HbA1c), LDL-C, and apolipoprotein B (ApoB) were significantly higher while those of high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A I (ApoA-I) were lower in MACCE positive group. NGAL correlated to body mass index (BMI) (r = 0.391, P = 0.001) and triglyceride (TG) (r = 0.228, P = 0.032), and high-sensitivity CRP (hsCRP) (r = 0.251, P = 0.007), and neutrophils (r = 0.454, P = 0.001), sdlDL-C level was found to be positively correlated with LDL-C (r = 0.413, P = 0.001), TG (r = 0.432, P = 0.001), and ApoB (r = 0.232, P = 0.002); and it was negatively correlated with HDL-C (r = -0.362, P = 0.031) and ApoA-I (r = -0.402, P = 0.001). Age-adjusted Cox regression analysis showed that NGAL (HR = 1.006, 95% confidence interval (CI): 1.005-1.008, P < 0.001) and sdLDL-C (HR = 1.052, 95% CI: 1.037-1.066, P < 0.001) were independently associated with occurrence of MACCE. ROC curve analysis showed that NGAL (area under ROC (AUC) = 0.79, 95% CI: 0.75-0.84, P < 0.001) and sdlDL-C (AUC = 0.76, 95% CI: 0.72-0.80, P < 0.001) could predict the occurrence of MACCE (area under ROC. NGAL combined with sdlDL-C could predict the occurrence of MACCE well (AUC = 0.87, 95% CI: 0.84-0.90, P < 0.001).

CONCLUSION

The higher NGAL and sdLDL-C in T2DM patients aged ≥ 65 years were significantly and independently associated with the risk of MACCE, and showed higher clinical values than other lipid biomarkers or other chronic inflammation, so they were expected to be the most effective predictors of MACCE assessment.

Comparison of the effects of triglyceride variability and exposure estimate on clinical prognosis in diabetic patients

BACKGROUND

Hypertriglyceridemia is an important feature of dyslipidemia in type 1 and type 2 diabetic patients and associated with the development of atherosclerotic cardiovascular disease. Recently, variability of lipid profile has been suggested as a residual risk factor for cardiovascular disease. This study compared the clinical impact of serum triglyceride variability, and their cumulative exposure estimates on cardiovascular prognosis in diabetic patients.

METHODS

A total of 25,933 diabetic patients who had serum triglyceride levels measured at least 3 times and did not have underlying malignancy, myocardial infarction (MI), and stroke during the initial 3 years (modeling phase) were selected from three tertiary hospitals. They were divided into a high/low group depending on their coefficient of variation (CV) and cumulative exposure estimate (CEE). Incidence of major adverse event (MAE), a composite of all-cause death, MI, and stroke during the following 5 years were compared between groups by multivariable analysis after propensity score matching.

RESULTS

Although there was a slight difference, both the high CV group and the high CEE group had a higher cardiovascular risk profile including male-dominance, smoking, alcohol, dyslipidemia, and chronic kidney disease compared to the low groups. After the propensity score matching, the high CV group showed higher MAE incidence compared to the low CV group (9.1% vs 7.7%, p = 0.01). In contrast, there was no significant difference of MAE incidence between the high CEE group and the low CEE group (8.6% vs 9.1%, p = 0.44). After the multivariable analysis with further adjustment for potential residual confounding factors, the high CV was suggested as an independent risk predictor for MAE (HR 1.19 [95% CI 1.03-1.37]).

CONCLUSION

Visit-to-visit variability of triglyceride rather than their cumulative exposure is more strongly related to the incidence of MAE in diabetic patients.

Atherogenic Lipoproteins for the Statin Residual Cardiovascular Disease Risk

Randomized controlled trials (RCTs) show that decreases in low-density lipoprotein cholesterol (LDL-C) by the use of statins cause a significant reduction in the development of cardiovascular disease (CVD). However, one of our previous studies showed that, among eight RCTs that investigated the effect of statins vs. a placebo on CVD development, 56–79% of patients had residual CVD risk after the trials. In three RCTs that investigated the effect of a high dose vs. a usual dose of statins on CVD development, 78–87% of patients in the high-dose statin arms still had residual CVD risk. The risk of CVD development remains even when statins are used to strongly reduce LDL-C, and this type of risk is now regarded as statin residual CVD risk. Our study shows that elevated triglyceride (TG) levels, reduced high-density lipoprotein cholesterol (HDL-C), and the existence of obesity/insulin resistance and diabetes may be important metabolic factors that determine statin residual CVD risk. Here, we discuss atherogenic lipoproteins that were not investigated in such RCTs, such as lipoprotein (a) (Lp(a)), remnant lipoproteins, malondialdehyde-modified LDL (MDA-LDL), and small-dense LDL (Sd-LDL). Lp(a) is under strong genetic control by apolipoprotein (a), which is an LPA gene locus. Variations in the LPA gene account for 91% of the variability in the plasma concentration of Lp(a). A meta-analysis showed that genetic variations at the LPA locus are associated with CVD events during statin therapy, independent of the extent of LDL lowering, providing support for exploring strategies targeting circulating concentrations of Lp(a) to reduce CVD events in patients receiving statins. Remnant lipoproteins and small-dense LDL are highly associated with high TG levels, low HDL-C, and obesity/insulin resistance. MDA-LDL is a representative form of oxidized LDL and plays important roles in the formation and development of the primary lesions of atherosclerosis. MDA-LDL levels were higher in CVD patients and diabetic patients than in the control subjects. Furthermore, we demonstrated the atherogenic properties of such lipoproteins and their association with CVD as well as therapeutic approaches.

Sex-specific changes in triglyceride profiles in liver cirrhosis and hepatitis C virus infection

Background

Hepatitis C virus (HCV) infection is associated with serum lipid abnormalities, which partly normalize following direct-acting antiviral (DAA) therapy. Here, associations of serum triglycerides (TGs) with viral genotype and markers of liver disease severity were evaluated in patients with chronic HCV. 

Methods

The study included the serum of 177 patients with chronic HCV. TGs were quantified by flow injection analysis Fourier transform mass spectrometry. Laboratory values and noninvasive scores for liver fibrosis assessment were determined. The nonparametric Kruskal‒Wallis test, one-way ANOVA, multiple linear regression and Student’s t test were used as appropriate. P values were adjusted for multiple comparisons.

Results

HCV-infected women had lower serum TGs than men, and thus, a sex-specific analysis was performed. None of the 46 TG species analyzed differed in the serum of female patients with and without liver cirrhosis. In contrast, in the serum of male patients with liver cirrhosis, TGs with 53, 56 and 58 carbon atoms and three to eight double bonds were diminished. These polyunsaturated TGs were also low in males with a high fibrosis-4 score. TGs with 7 or 8 double bonds negatively correlated with the model of end-stage liver disease score in males. In addition, TGs with 49, 51 and 53 carbon atoms were reduced in male patients infected with genotype 3a in comparison to genotype 1a. TGs with 56 carbon atoms were lower in genotype 3a-infected males than in genotype 1b-infected males. TGs did not differ in females by genotype. Genotype 3-related changes disappeared at the end of therapy with DAAs. Overall, the levels of serum TGs did not change during DAA therapy in either sex. Consequently, the serum TGs of males with liver cirrhosis were lower than those of males without cirrhosis at the end of therapy. Such a difference was not apparent in females.

Conclusions

The decline in TGs observed only in male patients with liver cirrhosis and male patients infected with genotype 3 illustrates sex-specific changes in lipid metabolism in chronic HCV.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01715-w.

Physiological Bases for the Superiority of Apolipoprotein B Over Low-Density Lipoprotein Cholesterol and Non-High-Density Lipoprotein Cholesterol as a Marker of Cardiovascular Risk

In 2019, the European Society of Cardiology/European Atherosclerosis Society stated that apolipoprotein B (apoB) was a more accurate marker of cardiovascular risk than low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol. Since then, the evidence has continued to mount in favor of apoB. This review explicates the physiological mechanisms responsible for the superiority of apoB as a marker of the cardiovascular risk attributable to the atherogenic apoB lipoprotein particles chylomicron remnants, very low-density lipoprotein, and low-density lipoprotein particles. First, the nature and relative numbers of these different apoB particles will be outlined. This will make clear why low-density lipoprotein particles are almost always the major determinants of cardiovascular risk and why the concentrations of triglycerides and LDL-C may obscure this relation. Next, the mechanisms that govern the number of very low-density lipoprotein and low-density lipoprotein particles will be outlined because, except for dysbetalipoproteinemia, the total number of apoB particles determines cardiovascular risk, Then, the mechanisms that govern the cholesterol mass within very low-density lipoprotein and low-density lipoprotein particles will be reviewed because these are responsible for the discordance between the mass of cholesterol within apoB particles, measured either as LDL-C or non-high-density lipoprotein cholesterol, and the number of apoB particles measured as apoB, which creates the superior predictive power of apoB over LDL-C and non-high-density lipoprotein cholesterol. Finally, the major apoB dyslipoproteinemias will be briefly outlined. Our objective is to provide a physiological framework for health care givers to understand why apoB is a more accurate marker of cardiovascular risk than LDL-C or non-high-density lipoprotein cholesterol.

Statin therapy is not warranted for a person with high LDL-cholesterol on a low-carbohydrate diet

PURPOSE OF REVIEW

Although there is an extensive literature on the efficacy of the low carbohydrate diet (LCD) for weight loss and in the management of type 2 diabetes, concerns have been raised that the LCD may increase cardiovascular disease (CVD) risk by increasing the level of low-density lipoprotein cholesterol (LDL-C). We have assessed the value of LDL-C as a CVD risk factor, as well as effects of the LCD on other CVD risk factors. We have also reviewed findings that provide guidance as to whether statin therapy would be beneficial for individuals with high LDL-C on an LCD.

RECENT FINDINGS

Multiple longitudinal trials have demonstrated the safety and effectiveness of the LCD, while also providing evidence of improvements in the most reliable CVD risk factors. Recent findings have also confirmed how ineffective LDL-C is in predicting CVD risk.

SUMMARY

Extensive research has demonstrated the efficacy of the LCD to improve the most robust CVD risk factors, such as hyperglycemia, hypertension, and atherogenic dyslipidemia. Our review of the literature indicates that statin therapy for both primary and secondary prevention of CVD is not warranted for individuals on an LCD with elevated LDL-C who have achieved a low triglyceride/HDL ratio.

Effects of pemafibrate on lipid metabolism in patients with type 2 diabetes and hypertriglyceridemia: A multi-center prospective observational study, the PARM-T2D study

AIMS

Pemafibrate, a novel selective peroxisome proliferator-activated receptor modulator, was shown to ameliorate lipid abnormalities in a phase III clinical trial of patients with type 2 diabetes mellitus (T2DM). However, its efficacy has not been demonstrated in real-world clinical practice in patients with T2DM.

METHODS

We performed a multi-center prospective observational study of the use of pemafibrate in patients with T2DM and hypertriglyceridemia versus conventional therapy, with or without a fibrate. The primary outcomes were the changes from baseline in fasting serum triglyceride (TG) and high-density lipoprotein-cholesterol (HDL-C) concentrations at week 52.

RESULTS

We recruited 650 patients, and data from 504 (252 per group) were analyzed after propensity score matching. In the pemafibrate group, both TG and HDL-C showed significant improvements (p < 0.001), and several indices reflecting TG-rich lipoproteins, low-density lipoprotein-cholesterol particle size, and liver enzyme elevations were significantly ameliorated compared with the control group, but there was no difference in glycemic control markers. One of the key secondary endpoints showed that switching from conventional fibrates to pemafibrate improved eGFR but increased uric acid concentration.

CONCLUSIONS

In patients with T2DM, pemafibrate has superior effects on lipid profile as well as liver and renal dysfunction to conventional fibrates.

Hypertriglyceridemia

Mild to moderate hypertriglyceridemia usually results from multiple small-effect variants in genes that control triglyceride metabolism. Hypertriglyceridemia is a critical component of the metabolic syndrome but can also occur secondary to several other conditions or drugs. Hypertriglyceridemia frequently is associated with an increased risk of cardiovascular disease (CVD). Statins are the mainstay of CVD prevention in hypertriglyceridemia, but eicosapentaenoic ethyl esters should be added in very-high-risk individuals. Although fibrates lower triglyceride levels, their role in CVD prevention remains unclear. Familial partial lipodystrophy is another relatively rare cause, although its true incidence is unknown.

N-3 fatty acid supplementation mediates lipid profile, including small dense LDL, when combined with statins: a randomized double blind placebo controlled trial

BACKGROUND

Epidemiological and clinical evidence suggests that high-dose intake of omega 3 fatty acids (n-3 FA) have a favorable role in altering serum triglycerides (TG) and non-high density lipoprotein cholesterol (non-HDL-C) when combined with statins in hyperlipidemic patients. Their efficacy in altering low-density lipoprotein cholesterol (LDL-C) particle size is yet to be established.

AIM

This study evaluated the effects of supplementing 4 g/day Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) on serum blood lipids, including small, dense LDL-C particle concentration, in hyperlipidemic patients receiving stable statin therapy.

METHODS

In this randomized, placebo-controlled, double-blind parallel group study, 44 patients on statin therapy for > 8 weeks with non-HDL-C concentrations above 130 mg/dL were randomized into two groups. For 8 weeks, together with their prescribed statin, the intervention group received 4 g/day EPA + DHA (3000 mg EPA + 1000 mg DHA in ethyl ester form) and the placebo group received 4 g/day olive oil (OO). Measurements of serum non-HDL-C, TG, total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), LDL-C (including large - LDL I; intermediate - LDL II; and small - LDL III subclasses), very-low-density lipoprotein cholesterol (VLDL-C) concentration, were taken at baseline and post-intervention. Dietary intake was assessed with a weighed intake, 3-day food diary at week 4. Primary outcome measures were percent change in LDL III, non-HDL-C and LDL particle number.

RESULTS

At the end of treatment, the median percent change in serum LDL III concentration was significantly greater in the n-3 FA group plus atorvastatin compared to placebo (- 67.5% vs - 0%, respectively; P < 0.001). Supplementation with n-3 FA plus atorvastatin led to significant reductions in serum non-HDL-C (- 9.5% vs 4.7%, P < 0.01), TG (- 21.5% vs 6.2%, P < 0.001) and VLDL-C (- 36.9% vs 4.0%, P < 0.001) and TC (- 6.6% vs 2.1%, P < 0.001). Between the groups, no significant difference in percent change in the serum concentration of LDL-C, HDL-C, as well as in the LDL I and LDL II subclasses was observed.

CONCLUSION

In this group of hyperlipidemic patients on a stable statin prescription, OM3 plus atorvastatin improved small dense LDL concentrations, non-HDL-C, VLDL-C and TG to a greater extent than atorvastatin alone. Further studies are warranted in this area.

TRIAL REGISTRATION

This trial was retrospectively registered on 23 May 2019 on ClinicalTrials.gov with ID: NCT03961763.

Lipid and Lipoprotein Metabolism

The exogenous lipoprotein pathway starts with the incorporation of dietary lipids into chylomicrons in the intestine. Chylomicron triglycerides are metabolized in muscle and adipose tissue and chylomicron remnants are formed, which are removed by the liver. The endogenous lipoprotein pathway begins in the liver with the formation of very low-density lipoprotein particles (VLDL). VLDL triglycerides are metabolized in muscle and adipose tissue forming intermediate-density lipoprotein (IDL), which may be taken up by the liver or further metabolized to low-density lipoprotein (LDL). Reverse cholesterol transport begins with the formation of nascent high-density lipoprotein (HDL) by the liver and intestine that acquire cholesterol from cells resulting in mature HDL. The HDL then transports the cholesterol to the liver either directly or indirectly by transferring the cholesterol to VLDL or LDL.

Low-density lipoprotein particles in atherosclerosis

Among the diseases causing human death, cardiovascular disease (CVD) remains number one according to the World Health Organization report in 2021. It is known that atherosclerosis is the pathological basis of CVD. Low-density lipoprotein (LDL) plays a pivotal role in the initiation and progression of atherosclerotic CVD (ASCVD). LDL cholesterol (LDL-C) is the traditional biological marker of LDL. However, large numbers of patients who have achieved the recommended LDL-C goals still have ASCVD risk. In multiple prospective studies, LDL particle (LDL-P) is reported to be more accurate in predicting CVD risk than LDL-C. LDL-Ps differ in size, density and chemical composition. Numerous clinical studies have proved that the atherogenic mechanisms of LDL-Ps are determined not only by LDL number and size but also by LDL modifications. Of note, small dense LDL (sdLDL) particles possess stronger atherogenic ability compared with large and intermediate LDL subfractions. Besides, oxidized LDL (ox-LDL) is another risk factor in atherosclerosis. Among the traditional lipid-lowering drugs, statins induce dramatic reductions in LDL-C and LDL-P to a lesser extend. Recently, proprotein convertase subtilsin/kexin type 9 inhibitors (PCSK9i) have been demonstrated to be effective in lowering the levels of LDL-C, LDL-P, as well as CVD events. In this article, we will make a short review of LDL metabolism, discuss the discordance between LDL-C and LDL-P, outline the atherogenic mechanisms of action of LDL by focusing on sdLDL and ox-LDL, summarize the methods used for measurement of LDL subclasses, and conclude the advances in LDL-lowering therapies using statins and PCSK9i.

The pattern of dyslipidaemia and factors associated with elevated levels of non-HDL-cholesterol among patients with type 2 diabetes mellitus in the Ho municipality: A cross sectional study

Background

Dyslipidaemia is a key comorbid condition of type 2 diabetes mellitus that increases the risk of cardiovascular disease. This study describes the pattern of dyslipidaemia and factors associated with elevated levels of non-high density lipoprotein cholesterol (HDL-C) among patients with type 2 diabetes mellitus in Ho.

Methods

This hospital-based cross-sectional study enrolled 210 patients with type 2 diabetes mellitus from Ho municipality. A semi-structured questionnaire was used to obtain demographic and other relevant parameters. Anthropometric, haemodynamic, and biochemical variables were obtained using standard methods. Dyslipidaemia was defined according to the Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) criteria while elevated levels of non-HDL-C was defined as non-HDL-C level ≥3.37 mmol/L. A Chi-square test and multivariate logistic regression analyses were performed to determine factors associated with elevated non-HDL-C levels.

Results

Overall, dyslipidaemia and elevated levels of non-HDL-C prevalence was 67.1% and 64.3%, respectively. The frequency of atherogenic, isolated, and mixed dyslipidaemias were 10.5%, 58.09% and 53.33 %, respectively. Females were four times more likely to develop elevated levels of non-HDL-C after adjustment for age (AOR: 4.07; CI: 2.20-7.51; p < 0.0001). Likewise, overweight (AOR: 3.1; CI: 1.45-6.61; p = 0.0035), grade 1 obesity (AOR: 2.8; CI: 1.20-6.49; p = 0.0168), and truncal obesity (AOR: 3.09; CI: 1.54-6.19; p < 0.0001) were three times each more likely to develop elevated levels of non HDL-C after adjustment for age and gender. However, alcohol intake was 66% unlikely to develop elevated levels of non-HDL-C (COR: 0.34; CI: 0.16-0.73; p = 0.006).

Conclusion

Dyslipidaemia and elevated levels of non-HDL-C were common in our study participants. Hypercholesterolaemia and co-occurrence of high TG and high LDL-C levels were the most prevalent isolated and mixed dyslipidaemias, respectively. The female gender, overweight, grade 1 obesity and truncal obesity, as well as alcohol intake were significant predictors of elevated levels of non-HDL-C.

Sorting through the extensive and confusing roles of sortilin in metabolic disease

Sortilin is a post-Golgi trafficking receptor homologous to the yeast vacuolar protein sorting receptor 10 (VPS10). The VPS10 motif on sortilin is a 10-bladed β-propeller structure capable of binding more than 50 proteins, covering a wide range of biological functions including lipid and lipoprotein metabolism, neuronal growth and death, inflammation, and lysosomal degradation. Sortilin has a complex cellular trafficking itinerary, where it functions as a receptor in the trans-Golgi network, endosomes, secretory vesicles, multivesicular bodies, and at the cell surface. In addition, sortilin is associated with hypercholesterolemia, Alzheimer's disease, prion diseases, Parkinson's disease, and inflammation syndromes. The 1p13.3 locus containing SORT1, the gene encoding sortilin, carries the strongest association with LDL-C of all loci in human genome-wide association studies. However, the mechanism by which sortilin influences LDL-C is unclear. Here, we review the role sortilin plays in cardiovascular and metabolic diseases and describe in detail the large and often contradictory literature on the role of sortilin in the regulation of LDL-C levels.

Lipoprotein Subclasses Independently Contribute to Subclinical Variance of Microvascular and Macrovascular Health

Lipoproteins are important cardiovascular (CV) risk biomarkers. This study aimed to investigate the associations of lipoprotein subclasses with micro- and macrovascular biomarkers to better understand how these subclasses relate to atherosclerotic CV diseases. One hundred and fifty-eight serum samples from the EXAMIN AGE study, consisting of healthy individuals and CV risk patients, were analysed with nuclear magnetic resonance (NMR) spectroscopy to quantify lipoprotein subclasses. Microvascular health was quantified by measuring retinal arteriolar and venular diameters. Macrovascular health was quantified by measuring carotid-to-femoral pulse wave velocity (PWV). Nineteen lipoprotein subclasses showed statistically significant associations with retinal vessel diameters and nine with PWV. These lipoprotein subclasses together explained up to 26% of variation (R2 = 0.26, F(29,121) = 2.80, p < 0.001) in micro- and 12% (R2 = 0.12, F(29,124) = 1.70, p = 0.025) of variation in macrovascular health. High-density (HDL-C) and low-density lipoprotein cholesterol (LDL-C) as well as triglycerides together explained up to 13% (R2 = 0.13, F(3143) = 8.42, p < 0.001) of micro- and 8% (R2 = 0.08, F(3145) = 5.46, p = 0.001) of macrovascular variation. Lipoprotein subclasses seem to reflect micro- and macrovascular end organ damage more precisely as compared to only measuring HDL-C, LDL-C and triglycerides. Further studies are needed to analyse how the additional quantification of lipoprotein subclasses can improve CV risk stratification and CV disease prediction.